Bright lights can worsen headaches, but a new study shows an LED light might do the opposite.

Doctors Mohab Ibrahim and Rajesh Khanna of the University of Arizona tested green LED lights and white LED lights on small samples of people with chronic migraines.

They found that the pain of the group looking at the green light dropped 40 to 50 percent. Participants in the trial were asked to stare at green LED lights for one-to-two hours a day over a 10-week period.

Even though the correlation of the green light and migraine pain is unknown, Ibrahim said it could be partially psychological. The green lights help regulate brain chemistry, Khanna said.

Essentially, what it’s doing is increasing your happy hormones, your level of endogenous opioids. The people in the green light group, they actually refused to return the green lights, and they wanted to keep it, so we let them keep it.

Despite the good results, both doctors said they hope to get grants from the Department of Defense and the National Institute of Health to expand the study.